Stoichiometry Lab Report

50. atomic radius, trends in the periodic table
As you go across the periodic table, the atomic radius decreases because the number of protons increases along with the number of electrons but the shielding does not change so they are more attracted to each other and the electrons are pulled more inward which makes the atomic radius smaller as you move across the periodic table.
51.
Rutherford’s experiments, gold foil, alpha particles
This requires a basic understanding of Rutherford’s experiment which is where he bombarded a very thin piece of gold foil with positively charged alpha particles and then witnessed scattering at a large angle which was indicative of a positive nucleus.
52.
Gases, phases, vapor pressure, solubility
Gases

dynamic equilibrium, exothermic and endothermic
For this problem, you need to remember that heat is just a piece of the reaction, either reactant or product depending on whether the overall reaction is exothermic or endothermic so adding heat would decrease K.
55.
limiting reagent, stoichiometry
Upon determining which one of the given reactants is the limiting reagent, simply use the balanced chemical equation, upon ascertaining that it is in fact balanced to find the desired number of moles of desired product. Would most simple to solve out each number of moles of each given reactant and then take the smallest result because that’s the limiting reagent
56.
insoluble and soluble compounds alkali metals are always soluble so NaI splits apart completely in solution so that means that any compound containing Na will be completely soluble so the compound that forms the precipitate has to contain I which has a charge of -1 and the first two have positive charges and compounds containing Pb are generally insoluble
57.
oxidation, reduction, half reactions, reduction

In the mountains, because of the altitude, the lower the atmospheric pressure so water boils at a lower temperature
59.
strong base and strong acid relationship
This questions requires basic stoichiometry and understanding that the reaction between a strong acid and a strong base will result in a salt and water and if it’s not a strong base then it will dissociate into some degree into OH-
60.
gas laws, standard conditions, PV=nRT
For this question, it is simple to all that you need to do is rearrange the equation PV=nRT to solve for pressure and convert the measurements to the ones used in the ideal gas law, K, mols, L and atm
61.
phase changes, heat of combustion, heat of solution, heat of vaporization, exothermic and endothermic reactions, thermochemistry
This questions requires an understanding that the heat of vaporization is an endothermic reaction rather than exothermic one that is combustion and so then it is necessary to subtract the energy required to change the phase from gaseous to liquid
62.
equilibrium constant, acid-base